android13/external/dagger2/java/dagger/producers/internal/DelegateProducer.java

112 lines
3.2 KiB
Java

/*
* Copyright (C) 2018 The Dagger Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dagger.producers.internal;
import static dagger.internal.Preconditions.checkNotNull;
import com.google.common.util.concurrent.ListenableFuture;
import dagger.internal.DoubleCheck;
import dagger.producers.Producer;
import javax.inject.Provider;
/**
* A DelegateProducer that is used to stitch Producer indirection during initialization across
* partial subcomponent implementations.
*/
public final class DelegateProducer<T> implements CancellableProducer<T> {
private CancellableProducer<T> delegate;
@Override
public ListenableFuture<T> get() {
return delegate.get();
}
// TODO(ronshapiro): remove this once we can reasonably expect generated code is no longer using
// this method
@Deprecated
public void setDelegatedProducer(Producer<T> delegate) {
setDelegate(this, delegate);
}
/**
* Sets {@code delegateProducer}'s delegate producer to {@code delegate}.
*
* <p>{@code delegateProducer} must be an instance of {@link DelegateProducer}, otherwise this
* method will throw a {@link ClassCastException}.
*/
public static <T> void setDelegate(Producer<T> delegateProducer, Producer<T> delegate) {
checkNotNull(delegate);
DelegateProducer<T> asDelegateProducer = (DelegateProducer<T>) delegateProducer;
if (asDelegateProducer.delegate != null) {
throw new IllegalStateException();
}
asDelegateProducer.delegate = (CancellableProducer<T>) delegate;
}
/**
* Returns the factory's delegate.
*
* @throws NullPointerException if the delegate has not been set
*/
CancellableProducer<T> getDelegate() {
return checkNotNull(delegate);
}
@Override
public void cancel(boolean mayInterruptIfRunning) {
delegate.cancel(mayInterruptIfRunning);
}
@Override
public Producer<T> newDependencyView() {
return new ProducerView<T>() {
@Override
Producer<T> createDelegate() {
return delegate.newDependencyView();
}
};
}
@Override
public Producer<T> newEntryPointView(final CancellationListener cancellationListener) {
return new ProducerView<T>() {
@Override
Producer<T> createDelegate() {
return delegate.newEntryPointView(cancellationListener);
}
};
}
private abstract static class ProducerView<T> implements Producer<T> {
private final Provider<Producer<T>> delegate =
DoubleCheck.provider(
new Provider<Producer<T>>() {
@Override
public Producer<T> get() {
return createDelegate();
}
});
abstract Producer<T> createDelegate();
@Override
public ListenableFuture<T> get() {
return delegate.get().get();
}
}
}